A liquid crystal display (LCD) device uses a backlight unit (BLU) as a light source because it does not emit light.
Examples of a light source that can be used for the BLU include CCFLs (cold cathode fluorescent lamps), EEFLs (external electrode fluorescent lamps), and LEDs (light emitting diodes). They are assembled to a chassis of the backlight unit to illuminate light onto a light guide plate, thereby providing light to an LCD device.